Ocean 'dead zones' exist -- and there are more of them than we thought

Scientists led by the Smithsonian Tropical Research Institute have discovered dead zones in a place where they least expected them: the Caribbean. More specifically, the tropics.

Dead zones are low-oxygen regions in the ocean where few sea life can survive. The main cause is human pollution. Until now, dead zones were thought to dominate mostly temperate zones on Earth, but the new study reveals that there are far more dead zones in the ocean than we thought.

The study also changes our outlook on the major threats to coral reefs. Before, warming oceans and acidification were the main concerns. But now, scientists must also consider dead zones as a major threat. Luckily, dead zones can be controlled relatively easily, unlike warming oceans and acidification, which would require an end to climate change.